Hi, I want to be able to plug my monitor into my stereo receiver to switch video sources like Computer, DVD, Cable, and VCR.My video card has an S-VIDEO out ...

Also make sure it can output signals in the VGA format. The prices of RF modulators can vary based on other features of the device. You should be able to find a basic model for under $50 as of 2013.

i have an old arcade game with a bad monitor, blown out flyback that is unobtainable. . tough to find a working 13 inch cga unit, and harder to find one ...

Getting a PCB made and soldering SMD resistors isn’t that hard, ... It is but one could always pick up a cheap HDMI to VGA converter for ~$3 to $5 that would probably get the job done.